Currently, various types of diepoxy compounds having an alicyclic skeleton per molecule are commercially available. Such diepoxy compounds are reacted with various curing agents and curing catalysts to produce cured products. These cured products of the diepoxy compounds can possess characteristics such as heat resistance, transparency and excellent dielectric characteristics peculiar to resins produced from compounds having an alicyclic skeleton, and these epoxy compounds are useful as components of coating agents, adhesives, inks or sealants or intermediates for producing compounds which are useful in the various final applications such as pharmaceutical agents or medical products.
Whilst, tetrahydroindene has been known to be by-produced upon synthesis of vinylnorbornene through a reaction of cyclopentadiene and 1,3-butadiene. In recent years, effective uses of tetrahydroindene have been sought.
For example, Patent Literature 1 discloses a method for producing a diepoxide of tetrahydroindene that is an epoxy compound having two alicyclic skeletons per molecule, from tetrahydroindene. Epoxy compounds with an alicyclic skeleton having no ester group in the molecule have been, therefore, demanded.
As a method for producing an epoxy compound, a method is known, in which olefins are oxidized with peracids such as peracetic acid. However, this method has problems that peracids require careful handling, and epoxides are reacted with carboxylic acids present in the reaction system thereby producing esters and the like, resulting in a decrease in the selectivity of the epoxides, and also that in production of an alicyclic epoxy compound regarded as having a high reactivity with acids, coexisting organic acids are likely reacted with epoxy groups produced in the presence of water, resulting in a decrease in the selectivity of the epoxides due to the ring-opening of the epoxy groups, and that the post-treatments are troublesome. Therefore, a method has been attracting attention, which uses hydrogen peroxide as an oxidation agent, which is easy in handling and turns to water that is harmless after the reaction.
As a method for producing an epoxy compound from olefins using hydrogen peroxide, a method is known in which epoxidation is carried out by reacting olefins and a hydrogen peroxide solution with a halogenated hydrocarbon as a solvent using a catalyst such as polyacids (Patent Literature 1). This method, however, has problems concerning halogen impurities in the products and environmental load due to the use of the halogenated hydrocarbon.
Patent Literature 3 discloses a solid phase reaction system for oxidation comprising a mixture of a powdered solid catalyst support and a powdered solid catalyst for oxidation reaction, an organic compound and a hydrogen peroxide solution.